# CVE-2019-9718: libavresample3: In FFmpeg 3.2 and 4.1, a denial of service in the subtitle decoder allows attackers to hog the CPU via a crafted vide...

CVE-2019-9718 is fixed in 14 products on 1 platform, first by ffmpeg 7:3.4.6-0ubuntu0.18.04.1, released April 17, 2019. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2019-9718
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0157
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 11, 2019

## Description

In FFmpeg 3.2 and 4.1, a denial of service in the subtitle decoder allows attackers to hog the CPU via a crafted video file in Matroska format, because ff_htmlmarkup_to_ass in libavcodec/htmlsubtitles.c has a complex format argument to sscanf.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | ffmpeg Ubuntu 18.04.6 LTS (bionic) | 7:3.4.6-0ubuntu0.18.04.1 | [ffmpeg 7:3.4.6-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-ffmpeg-7-3.4.6-0ubuntu0.18.04.1.md) | Apr 17, 2019 |
| Linux | libavcodec-extra Ubuntu 18.04.6 LTS (bionic) | 7:3.4.6-0ubuntu0.18.04.1 | [libavcodec-extra 7:3.4.6-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libavcodec-extra-7-3.4.6-0ubuntu0.18.04.1.md) | Apr 17, 2019 |
| Linux | libavcodec-extra57 Ubuntu 18.04.6 LTS (bionic) | 7:3.4.6-0ubuntu0.18.04.1 | [libavcodec-extra57 7:3.4.6-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libavcodec-extra57-7-3.4.6-0ubuntu0.18.04.1.md) | Apr 17, 2019 |
| Linux | libavcodec57 Ubuntu 18.04.6 LTS (bionic) | 7:3.4.6-0ubuntu0.18.04.1 | [libavcodec57 7:3.4.6-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libavcodec57-7-3.4.6-0ubuntu0.18.04.1.md) | Apr 17, 2019 |
| Linux | libavdevice57 Ubuntu 18.04.6 LTS (bionic) | 7:3.4.6-0ubuntu0.18.04.1 | [libavdevice57 7:3.4.6-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libavdevice57-7-3.4.6-0ubuntu0.18.04.1.md) | Apr 17, 2019 |
| Linux | libavfilter-extra Ubuntu 18.04.6 LTS (bionic) | 7:3.4.6-0ubuntu0.18.04.1 | [libavfilter-extra 7:3.4.6-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libavfilter-extra-7-3.4.6-0ubuntu0.18.04.1.md) | Apr 17, 2019 |
| Linux | libavfilter-extra6 Ubuntu 18.04.6 LTS (bionic) | 7:3.4.6-0ubuntu0.18.04.1 | [libavfilter-extra6 7:3.4.6-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libavfilter-extra6-7-3.4.6-0ubuntu0.18.04.1.md) | Apr 17, 2019 |
| Linux | libavfilter6 Ubuntu 18.04.6 LTS (bionic) | 7:3.4.6-0ubuntu0.18.04.1 | [libavfilter6 7:3.4.6-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libavfilter6-7-3.4.6-0ubuntu0.18.04.1.md) | Apr 17, 2019 |
| Linux | libavformat57 Ubuntu 18.04.6 LTS (bionic) | 7:3.4.6-0ubuntu0.18.04.1 | [libavformat57 7:3.4.6-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libavformat57-7-3.4.6-0ubuntu0.18.04.1.md) | Apr 17, 2019 |
| Linux | libavresample3 Ubuntu 18.04.6 LTS (bionic) | 7:3.4.6-0ubuntu0.18.04.1 | [libavresample3 7:3.4.6-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libavresample3-7-3.4.6-0ubuntu0.18.04.1.md) | Apr 17, 2019 |
| Linux | libavutil55 Ubuntu 18.04.6 LTS (bionic) | 7:3.4.6-0ubuntu0.18.04.1 | [libavutil55 7:3.4.6-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libavutil55-7-3.4.6-0ubuntu0.18.04.1.md) | Apr 17, 2019 |
| Linux | libpostproc54 Ubuntu 18.04.6 LTS (bionic) | 7:3.4.6-0ubuntu0.18.04.1 | [libpostproc54 7:3.4.6-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libpostproc54-7-3.4.6-0ubuntu0.18.04.1.md) | Apr 17, 2019 |
| Linux | libswresample2 Ubuntu 18.04.6 LTS (bionic) | 7:3.4.6-0ubuntu0.18.04.1 | [libswresample2 7:3.4.6-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libswresample2-7-3.4.6-0ubuntu0.18.04.1.md) | Apr 17, 2019 |
| Linux | libswscale4 Ubuntu 18.04.6 LTS (bionic) | 7:3.4.6-0ubuntu0.18.04.1 | [libswscale4 7:3.4.6-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libswscale4-7-3.4.6-0ubuntu0.18.04.1.md) | Apr 17, 2019 |

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